This invention belongs to the art of agricultural organic chemistry, and provides to the art an unusually facile synthesis of herbicidal pyridazinones.
Previous syntheses of pyridazinones have been quite difficult, and have required unusual intermediate compounds. For example, Breslow et al., "Diphenylcyclopropenone", J. Am. Chem. Soc. 87, 1320-25 (1965), and Izzo et al., "Reaction of Diazomethane with Cyclopropenones", Chem. & Ind. 839-40 (1964), disclosed processes for making 3,5-diphenyl-4(1H)-pyridazinone. One of their reaactants, diazomethane, is a hazardous compound, and the other reactant, cyclopropenone, is extremely difficult of access.